NASA probe wakes up for Pluto encounter

A NASA probe launched eight years ago to explore Pluto has woken up from its last hibernation in deep space and is now preparing to take first detailed images of the dwarf planet's surface and its moons in July 2015.

Launched in January 2006, New Horizon probe has travelled nearly 4.6 billion kms on its way to study Pluto, its largest moon Charon and a few smaller moons, Space.com reported.

During its journey, New Horizons passed three to four times closer to Jupiter, using the planet's gravity to increase its speed and reduce journey times to Pluto by three years.

While the probe is now out of its hibernation phase, it will still take seven months to reach its closet point from Pluto, passing within 12,500 kms of the planet's surface in July 2015.

The probe sends a weekly signal back to Earth, and is woken up every six to 10 months to assure that it is still operational.

"It is tremendously exciting because even though we have hibernated 18 times and recovered each time, this is the one that really counts," Harold Weaver, the project scientist for the New Horizons mission at Johns Hopkins APL, was quoted as saying.

The probe carries seven instruments including infrared and ultraviolet spectrometres, a multi-colour camera, a high-resolution telescopic camera, and a space dust detector.

All of the instruments aboard New Horizons draw power from a radioisotope thermoelectric generator - a type of nuclear motor - which provides less power than a pair of 100watt light bulbs.

New Horizon will also probe several small, icy bodies in the Kupier Belt - the most densely populated part of our solar system, the report added.